Metal–metal bonding in co-ordination complexes. Part VI. Crystal structure of dicarbonylcyclopentadienyl(trichlorostannyl)iron

Abstract

The crystal and molecular structure of dicarbonyl-π-cyclopentadienyl(trichlorostannyl)iron has been determined by X-ray methods using the intensities of 2561 spectra measured by counter diffractometry. The crystals are triclinic, space group P, a= 11·018(2), b= 8·357(1), c= 6·627(1)Å, α= 106·24(1), β= 84·77(1), γ= 96·39(1)°, Z= 2. The structure was determined by the heavy atom method and refined by block-diagonal least-squares techniques with individual anisotropic thermal parameters to R= 0·039.

The molecule contains a short Sn–Fe bond, 2·467(2)Å, and evidence is presented that this is a σ-bond. The Fe–Sn–Cl and Cl–Sn–Cl angles lie in the ranges 116–121° and 96–100° respectively. The Sn–Cl bond lengths are 2·350(2), 2·358(2), and 2·373(2)Å. Mean bond lengths in the (π-C₅H₅)Fe(CO)₂ moiety are : Fe–C(ring), 2·092(3); Fe–C, 1·785(6); C–O, 1·130(8); and C–C, 1·408(5)Å. Molecular interactions are of normal van der Waals type and there are no abnormally short intra- or inter-molecular contacts.